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  • AAO PPP Cornea/External Disease Committee, Hoskins Center for Quality Eye Care
    Cornea/External Disease
    By the American Academy of Ophthalmology Preferred Practice Pattern Cornea/External Disease Committee: Michelle K. Rhee, MD,1 Sumayya Ahmad, MD, Methodologist,2 Guillermo Amescua, MD,3 Albert Y. Cheung, MD,4 Daniel S. Choi, MD,5 Vishal Jhanji, MD, FRCS, FRCOphth,6 Amy Lin, MD,7 Shahzad I. Mian, MD,8 Elizabeth T. Viriya, MD,9 Francis S. Mah, MD, Co-Chair,10 Divya M. Varu, MD, Co-Chair11

    As of November 2015, the PPPs are initially published online only in the Ophthalmology journal and may be freely downloaded in their entirety by all visitors. Open the PDF for this entire PPP or click here to access the PPP on the journal's site. Click here to access the journal's PPP collection page

    1Department of Ophthalmology, Icahn School of Medicine at Mount Sinai, Elmhurst Hospital, Mount Sinai Services, Elmhurst, New York
    2Department of Ophthalmology, New York Eye and Ear Infirmary of Mount Sinai, New York, New York
    3Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida
    4Virginia Eye Consultants, Norfolk, Virginia, Assistant Professor, Department of Ophthalmology, Eastern Virginia Medical School
    5Cataract and Vision Center of Hawaii, Honolulu, Hawaii
    6Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
    7John A. Moran Eye Center, University of Utah, Salt Lake City, Utah
    8Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, Michigan
    9Department of Ophthalmology, Lincoln Hospital/NYC Health+ Hospitals, Bronx, New York
    10Departments of Cornea and External Diseases, Scripps Clinic Torrey Pines, La Jolla, California
    11Dell Laser Consultants, Austin, Texas

    Highlighted Findings and Recommendations for Care


    The majority of community-acquired cases of bacterial keratitis that are small noncentral ulcers resolve with topical empiric therapy. However, smears and/or cultures are specifically indicated in certain circumstances.


    Contact lens wear is the number-one risk factor for microbial keratitis in the United States. Overnight wear (including orthokeratology) is a major risk factor for infection. In many other parts of the world trauma is the leading risk factor for bacterial keratitis.


    Topical antibiotics should be prescribed to prevent acute infection in patients with a corneal abrasion who wear contact lenses or suffered trauma. In these patients, patching the eye early on is not advised because these increase the risk of secondary bacterial keratitis.


    When treating microbial keratitis, corticosteroids may be considered after 48 hours of antibiotic therapy when the causative organism is identified and/or the infection has responded to therapy. Corticosteroids should be avoided in cases of suspected Acanthamoeba, Nocardia, or fungus. The efficacy of the therapeutic regimen is judged primarily by the clinical response. In Pseudomonas and other gram-negative keratitis, there may be increased inflammatory signs during the first 24 to 48 hours despite appropriate therapy.


    Froom 2005 to 2015 there was increased resistance of methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa to topical fluoroquinolones.

    Literature Search


    Bacterial Keratitis - 2023 - Literature Search